Floor care appliances including vacuum cleaners equipped with dirt cup assemblies providing cyclonic cleaning action are well known in the art. Examples of such vacuum cleaners may be found in, for example, issued U.S. Pat. Nos. 7,640,624 and 7,908,707 as well as published U.S. Patent Application 2011/0225764 all assigned to the assignee of the present document.
Such cyclonic vacuum cleaners generally include a dirt cup with an arcuate and generally cylindrical sidewall, a tangentially directed air inlet provided in that side wall and an axially directed air outlet provided in an end of the dirt cup. The air outlet is covered with a filter shroud that is concentrically received within the arcuate side wall of the dirt cup.
During operation, air entrained dirt and debris is drawn into the vacuum cleaner and delivered to the dirt cup through the tangentially directed inlet. The air stream swirls around the arcuate sidewall so as to provide cyclonic air flow. Particles in the air stream act under centrifugal force and are accelerated toward engagement with the side wall with the resulting friction slowing the particles so that they drop downwardly toward the bottom of the dirt cup where they are collected. Relatively clean air is then drawn through the filter shroud and discharged through the axially directed outlet.
This document describes a vacuum cleaner having a dirt cup assembly with an arcuate sidewall incorporating ribs that function to enhance the cleaning efficiency of the vacuum cleaner.